FourLabs Blog
Practical, in-depth guides on the math, formulas and conventions behind every FourLabs tool — newest first.
- Dev & Design Lab
How to Create a Strong Password in 2026 (Length, Entropy & Real Attacks)
Why length beats complexity, how entropy is measured in bits, how attackers actually crack passwords, and the exact settings to use in a secure password generator.
Read More
- Dev & Design Lab
Lorem Ipsum: What It Actually Means & When to Use Placeholder Text
Where 'Lorem ipsum dolor sit amet' really comes from, why designers still use it, when to swap it for real copy, and the alternatives when you need something different.
Read More
- Text Lab
Invisible Text: How It Works, Where It Works, Where It Doesn't
Which Unicode characters render as blank space, which platforms strip them, and why your blank WhatsApp message sometimes refuses to send.
Read More
- Text Lab
Find and Replace with Regex: A No-Nonsense Cheat Sheet
The regex patterns that pay for themselves: emails, phone numbers, whitespace cleanup, capture groups and the difference between greedy and lazy matching.
Read More
- Conversion Lab
Celsius, Fahrenheit & Kelvin: Formulas, Reference Points & Memory Tricks
The exact formulas for converting between Celsius, Fahrenheit, Kelvin, Rankine and Réaumur, plus reference points every cook, traveller and student should memorise.
Read More
- Daily Tech Lab
Calorie Calculator Explained: BMR, TDEE & Macro Targets
What BMR and TDEE actually mean, the Mifflin–St Jeor formula, activity multipliers, and how to set protein, carb and fat targets for any goal.
Read More
- Text Lab
Writing Numbers in Words: Checks, Invoices & Legal Documents
Why amounts are written twice on cheques, the exact phrasing banks expect, and how the same rules apply to invoices, loan agreements, contracts and tax forms in the US, UK and India.
Read More
- Daily Tech Lab
Percentage Calculator Guide: Increase, Decrease & Tip Math Made Simple
Master the three core percentage formulas — what is X% of Y, X is what % of Y, and percent change — with real-world examples for tips, discounts and tax.
Read More
- Daily Tech Lab
How to Calculate Your Exact Age (Years, Months, Days & Leap Years)
The simple method to calculate age in years, months and days — including how leap years and month-length differences affect the result.
Read More
- Text Lab
UPPERCASE, camelCase, snake_case & Slugs: When to Use Each
A practical guide to text case conventions: when to use Title Case in headings, camelCase in JavaScript, snake_case in databases and kebab-case in URLs.
Read More